ISO 9876:2015 pdf free
ISO 9876:2015 pdf free.Ships and marine technology一Marine facsimile receivers for meteorological charts
Except where otherwise stated, electric power shall be supplied to the equipment only during the periods specified for electrical tests and performance tests.
Except where otherwise stated, the supply voltage applied to the equipment during the tests shall be the nominal voltage and alternating current supplies shall be at nominal frequency.
Any requirements in Clause 4 for which no test is specified in Clause 5 shall be checked by inspection of the equipment, its manufacturing drawings, or other relevant documents.
Recording unit testing shall be undertaken using a facsimile transmitter linked to the recorder under test. If the transmitter is of AM output, it shalll be linked through an AM/FM converter. The transmitter shall be capable of operating in accordance with the requirements given in 4.2.2 to 4.2.5.
The type testing authority has the option of evaluating overall performance of the equipment by receiving an actual facsimile transmission
The radio receiver shall be tested by reception of signals of F3C class of emission from a signal generator while linked to the recording unit.
The spurious response rejection ratio is the ratio of the input level of an unwanted signal at the frequency of the spurious response to the input level of a wanted signal when the wanted and unwanted signals individually produce the same SND/N or SND/ND ratio at the receiver output.
The receiver shall be adjusted in compliance with the arrangement for measurement of sensitivity. The carrier frequency of the input signal shall then be adjusted to the image and intermediate frequencies.
For the image and intermediate frequencies, the carrier frequency of the input signal shall be adjusted to give maximum output power. The input level shall then be adjusted to give an SND/N or SND/ND ratio of 20 dB at the output of the receiver. The ratio between the input level of each spurious signal and the input level to the wanted signal shall then be evaluated.ISO 9876 pdf download.
